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Jp Talbot - One of the best experts on this subject based on the ideXlab platform.

  • The significance of source-receiver interaction in the response of piled foundations to ground-borne vibration from underground Railways
    2021
    Co-Authors: Tl Edirisinghe, Jp Talbot
    Abstract:

    The numerical prediction of vibration in buildings due to underground Railways involves modelling many physical phenomena. Not least of these is the dynamic soil-structure interaction that exists between the various elements of the system. The majority of existing models assume that the interaction between the Railway tunnel and the building's foundation is negligible, with the two sub-systems behaving as though they are uncoupled. This paper presents some initial results from a three-dimensional model that accounts for the through-soil coupling between a tunnel and a piled foundation. The model is based on the pipe-in-pipe model, of a circular, longitudinally invariant tunnel excited by wheel-Rail Roughness, coupled to a boundary-element model of the foundation using an iterative wave-scattering approach. Initial test cases, involving single piles and pile-groups, highlight new details of tunnel-pile and pile-pile interaction, as well as predicting the effect of piles on ground vibration levels

  • On the derivation of Rail Roughness spectra from axle-box vibration: Development of a new technique
    2019
    Co-Authors: Td Carrigan, Fidler Pra, Jp Talbot
    Abstract:

    Railhead Roughness on Railways is a cause of noise and vibration. Corrugation (a periodic form of Roughness) can grow rapidly and unpredictably, generating high levels of noise and vibration. An emerging technique for monitoring Rail Roughness is by use of axle-box accelerometers on in-service trains, which can be more cost-effective than conventional inspection methods. Axle-box accelerometers measure the vibration induced by Roughness, rather than the Roughness itself, and hence require signal processing techniques to translate this vibration into suitable metrics of the Railhead condition, such as a wavelength spectrum of Roughness. This paper presents progress towards a new stochastic frequency-domain inverse method that derives wavelength-spectra of Rail Roughness from axle-box acceleration measurements. This method compensates for the effects of vehicle speed and track dynamic behaviour on axle-box acceleration, which have adversely affected previous methods that, for example, rely on calibration on a reference section of track or simply take the RMS of the axle-box acceleration. The practical implications of processing and presenting measurements in the frequency domain are discussed, including the effect of varying vehicle speed and the trade-off between resolution and statistical accuracy. An initial algorithm is proposed and demonstrated through timedomain simulations of a theoretical vehicle-track model. Accurate derivation of Roughness from axle-box acceleration will facilitate future development of autonomous monitoring systems fitted to in-service trains that continuously 'map' the condition of a Rail network in real time, enabling more efficient and proactive scheduling of Rail maintenance

  • lift over crossings as a solution to tram generated ground borne vibration and re radiated noise
    Proceedings of the Institution of Mechanical Engineers Part F: Journal of Rail and Rapid Transit, 2014
    Co-Authors: Jp Talbot
    Abstract:

    The operation of trams close to sensitive buildings can lead to concerns over ground-borne vibration and re-radiated noise. Vibration generated at the wheel/Rail interface propagates through the track structure, through the ground and into buildings, where it may cause disturbance as perceptible vibration and/or re-radiated noise. This paper presents work undertaken to solve a re-radiated noise problem within the auditorium of the Royal Concert Hall, Nottingham, UK. The hall is situated alongside a crossover between two tracks of Nottingham’s Express Transit tramway. Initial measurements established the dominance of re-radiated noise over airborne noise. Simultaneous noise and vibration measurements were then used to establish the relative significance of the impulsive vibration generated at the various Rail discontinuities of the crossover, compared with the essentially continuous vibration due to wheel/Rail Roughness. The results led to the selection of a new ‘lift-over’ crossing, together with an improved design of switch, as the basis for solving the problem. The paper includes descriptions of the experimental methods, together with a summary of the results. The new crossover design is described and the results of the commissioning measurements are presented as a final demonstration of the new lift-over crossing’s performance.

An Dong - One of the best experts on this subject based on the ideXlab platform.

  • Investigation on Rail corrugation grinding criterion based on coupled vehicle–track dynamics and rolling contact fatigue model
    'SAGE Publications', 2021
    Co-Authors: Liang Hongqin, Li Wei, Zhou Zhijun, Wen Zefeng, Li S., An Dong
    Abstract:

    Based on the measured spectra of Rail Roughness and track structures longitudinal Roughness, the Rail grinding limit is studied with the help of an established coupled dynamic metro vehicle–track model and a rolling contact fatigue model. The results indicate that metro Rail grinding control should be regulated according to corrugation wavelength range and operating speed. Based on the rolling contact fatigue model, longer wavelength of Rail corrugation has less influence on the wheel rolling contact fatigue. For the metro lines with a maximum operating speed of 80 km/h, the average levels of Rail corrugation in the wavelength ranges of 30–65 mm, 65–125 mm, and 125–250 mm should be less than 5.4, 24.8, and 33.8 dB re 1 μm, respectively; for the ones with the operating speed of 80–120 km/h, the corresponding average corrugation levels in the three wavelength ranges should be less than 4.4, 9.8, and 29.8 dB re 1 μm, respectively.

  • Investigation on Rail corrugation grinding criterion based on coupled vehicle–track dynamics and rolling contact fatigue model
    'SAGE Publications', 2021
    Co-Authors: Liang Hongqin, Li Wei, Zhou Zhijun, Wen Zefeng, Li S., An Dong
    Abstract:

    Based on the measured spectra of Rail Roughness and track structures longitudinal Roughness, the Rail grinding limit is studied with the help of an established coupled dynamic metro vehicle–track model and a rolling contact fatigue model. The results indicate that metro Rail grinding control should be regulated according to corrugation wavelength range and operating speed. Based on the rolling contact fatigue model, longer wavelength of Rail corrugation has less influence on the wheel rolling contact fatigue. For the metro lines with a maximum operating speed of 80 km/h, the average levels of Rail corrugation in the wavelength ranges of 30–65 mm, 65–125 mm, and 125–250 mm should be less than 5.4, 24.8, and 33.8 dB re 1 μm, respectively; for the ones with the operating speed of 80–120 km/h, the corresponding average corrugation levels in the three wavelength ranges should be less than 4.4, 9.8, and 29.8 dB re 1 μm, respectively.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Railway Engineerin

Liang Hongqin - One of the best experts on this subject based on the ideXlab platform.

  • Investigation on Rail corrugation grinding criterion based on coupled vehicle–track dynamics and rolling contact fatigue model
    'SAGE Publications', 2021
    Co-Authors: Liang Hongqin, Li Wei, Zhou Zhijun, Wen Zefeng, Li S., An Dong
    Abstract:

    Based on the measured spectra of Rail Roughness and track structures longitudinal Roughness, the Rail grinding limit is studied with the help of an established coupled dynamic metro vehicle–track model and a rolling contact fatigue model. The results indicate that metro Rail grinding control should be regulated according to corrugation wavelength range and operating speed. Based on the rolling contact fatigue model, longer wavelength of Rail corrugation has less influence on the wheel rolling contact fatigue. For the metro lines with a maximum operating speed of 80 km/h, the average levels of Rail corrugation in the wavelength ranges of 30–65 mm, 65–125 mm, and 125–250 mm should be less than 5.4, 24.8, and 33.8 dB re 1 μm, respectively; for the ones with the operating speed of 80–120 km/h, the corresponding average corrugation levels in the three wavelength ranges should be less than 4.4, 9.8, and 29.8 dB re 1 μm, respectively.

  • Investigation on Rail corrugation grinding criterion based on coupled vehicle–track dynamics and rolling contact fatigue model
    'SAGE Publications', 2021
    Co-Authors: Liang Hongqin, Li Wei, Zhou Zhijun, Wen Zefeng, Li S., An Dong
    Abstract:

    Based on the measured spectra of Rail Roughness and track structures longitudinal Roughness, the Rail grinding limit is studied with the help of an established coupled dynamic metro vehicle–track model and a rolling contact fatigue model. The results indicate that metro Rail grinding control should be regulated according to corrugation wavelength range and operating speed. Based on the rolling contact fatigue model, longer wavelength of Rail corrugation has less influence on the wheel rolling contact fatigue. For the metro lines with a maximum operating speed of 80 km/h, the average levels of Rail corrugation in the wavelength ranges of 30–65 mm, 65–125 mm, and 125–250 mm should be less than 5.4, 24.8, and 33.8 dB re 1 μm, respectively; for the ones with the operating speed of 80–120 km/h, the corresponding average corrugation levels in the three wavelength ranges should be less than 4.4, 9.8, and 29.8 dB re 1 μm, respectively.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Railway Engineerin

Denia Guzmán, Francisco David - One of the best experts on this subject based on the ideXlab platform.

  • Improved Railway wheelset-track interaction model in the high-frequency domain
    'Elsevier BV', 2017
    Co-Authors: Martínez Casas José, Giner Navarro Juan, Baeza González, Luis Miguel, Denia Guzmán, Francisco David
    Abstract:

    [EN] As it is well known, there are various phenomena related to Railway train-track interaction, some of them caused by the high frequency dynamics of the system, such as rolling noise when the vehicle runs over the track, as well as squeal noise and short-pitch Rail corrugation for curved tracks. Due to these phenomena and some others unsolved so far, a large effort has been made over the last 40 years in order to define suitable models to study the train-track interaction. The introduction of flexibility in wheelset and Rail models was required to have a more realistic representation of the wheel-Rail interaction effects at high frequencies. In recently published train-track interaction models, the Rails are modelled by means of Timoshenko beam elements, valid up to 1.5 kHz for lateral Rail vibration and up to 2 kHz for vertical vibration. This confines the frequency range of validity for the complete train-track model to 1.5 kHz. With the purpose of extending the range of validity above 1.5 kHz, a 3D track model based on the Moving Element Method (MEM) is developed in this paper to replace the Timoshenko beam considered in earlier studies, adopting cyclic boundary conditions and Eulerian coordinates. The MEM approach considers a mobile Finite Element (FE) mesh which moves with the vehicle, so the mass of the Rail flows with the vehicle speed but in the opposite direction through the mesh. Therefore, the MEM permits to fix the contact area in the middle of a finitely long track and to refine the mesh only around the contact area, where the forces and displacements will be more significant. Additionally, a modal approach is adopted in order to reduce the number of degrees of freedom of the Rail model. Both strategies lower substantially the computational cost. Simulation results are presented and discussed for different excitation sources including random Rail Roughness and singularities such as wheel flats. All the simulation cases are carried out for a Timoshenko beam and a 3D MEM track model in order to point out the differences in the contact forces above the range of validity of the Timoshenko beam.The authors gratefully acknowledge the financial support of Ministerio de Economía y Competitividad and the European Regional Development Fund (project TRA2013-45596-C2-1-R), as well as Generalitat Valenciana (project Prometeo/2012/023) and Ministerio de Educación, Cultura y Deporte (project SP20140659) as part of Programa Campus de Excelencia Internacional.Martínez Casas, J.; Giner Navarro, J.; Baeza González, LM.; Denia Guzmán, FD. (2017). Improved Railway wheelset-track interaction model in the high-frequency domain. Journal of Computational and Applied Mathematics. 309(1):642-653. doi:10.1016/j.cam.2016.04.034S642653309

Anders Ekberg - One of the best experts on this subject based on the ideXlab platform.

  • acceptance criterion for Rail Roughness level spectrum based on assessment of rolling contact fatigue and rolling noise
    Wear, 2011
    Co-Authors: Jens C O Nielsen, Anders Ekberg
    Abstract:

    The influences of train speed and Rail Roughness level on rolling noise and subsurface initiated rolling contact fatigue (RCF) impact are studied. In particular, the consequences of short-pitch Rail corrugation on tangent track with wavelengths in the interval 3-8 cm are simulated using models of dynamic vehicle-track interaction. Based on the calculated results, a criterion in terms of a limit for maximum levels of Rail Roughness with respect to the current traffic conditions can be determined. Such a criterion may be useful for planning of Rail grinding intervals if used together with a system for regular monitoring of Rail Roughness levels. It is concluded that the importance of controlling Rail Roughness increases with increasing train speed. Increasing axle loads on freight vehicles from 22.5 tonnes to 30 tonnes leads to a significant increase in RCF impact. In operational practice, this is usually compensated for by introducing more conformal wheel-Rail profile combinations. Calculated vertical wheel-Rail contact forces and rolling noise levels show good agreement with field measurements.

  • acceptance criterion for Rail Roughness level spectrum based on assessment of rolling contact fatigue and rolling noise
    Proceedings of the 8th International Conference on Contact Mechanics and Wear of Rail Wheel Systems, 2009
    Co-Authors: Jens C O Nielsen, Anders Ekberg
    Abstract:

    The influences of train speed and Rail Roughness level on rolling noise and subsurface initiated rolling contact fatigue (RCF) impact are studied. In particular, the consequences of short-pitch Rail corrugation on tangent track with wavelengths in the interval 3 – 8 cm are simulated using models of dynamic vehicle–track interaction. Based on the calculated results, a criterion in terms of a limit for maximum levels of Rail Roughness can be determined. Such a criterion may be useful for planning of Rail grinding intervals if used together with a system for regular monitoring of Rail Roughness levels. It is concluded that the importance of controlling Rail Roughness increases with increasing train speed. Increasing axle loads on freight vehicles from 22.5 tonnes to 30 tonnes leads to a significant increase in RCF impact. In operational practice, this is usually compensated for by introducing more conformal wheel–Rail profile combinations. Calculated vertical wheel–Rail contact forces and rolling noise levels show good agreement with field measurements